Chemically Grafted Aminated Carbon Nanotubes and l-Lysine in Ultramodified Conditions for Carbon Dioxide Storage

The study reported CO₂ storage properties of single-walled carbon nanotubes (CNTs) modified by introducing amino groups onto CNT surfaces via a chemical process. Two different approaches were used to produce amino-functionalized nanotubes by adding lithium amide and l-lysine amino acid. Lithium amide was introduced on CNT surfaces, and then, it was further modified by adding amino-moiety (l-lysine amino acid) to obtain multiamino sites on the CNT surface for CO₂ storage. The aminated CNT were followed by CO₂ adsorption experiments, and amino group interactions with CO₂ have helped CNT to achieve higher adsorption capacity. The successful modification of CNTs showed ameliorated CO₂ storage capacity as compared to pristine CNT. The modified CNT possessed free amine groups on the surface, which led to an enhanced CO₂ adsorption capacity. The modified CNT samples were analyzed by X-ray photoelectron spectroscopy, infrared spectroscopy, and X-ray diffraction techniques.